The Account Manager provides an overview of user and group system installed on ClearOS.
If your system does not have this app available, you can install it via the Marketplace.
You can find this feature in the menu system at the following location:
System|Accounts Manager|Account Manager
Here you will find a list of plugins which a user will need specific authorisation to use;
By clicking on the you can add or remove users' access to that plugin.
The same can also be achieved in the Systems|Accounts|Users screen and in the individual app screens.